1. Field of the Invention
The present invention relates to thermal modulating control valves and more particularly to a thermal modulating control valve of the type used in aircraft for supplying bleed air at regulated flow rates for aircraft anti-icing systems. More particularly, the new and improved thermal modulating control valve of the present invention is especially adapted for use in aircraft having a plurality of sources of bleed air available for use in aircraft anti-icing and other aircraft operating systems such as air conditioning, cabin pressurization and air turbine drive systems, etc.
2. Background of the Prior Art
In modern day jet aircraft, many aircraft systems are operated with "bleed air" which comprises pressurized high temperature air supplied from compressor sections of the jet turbine engines. Bleed air control valves for supplying bleed air to various aircraft systems at thermally modulated temperatures must necessarily be capable of withstanding relatively high temperatures up to 800.degree. F. and must have a long and useful service life with a fail-safe feature designed to provide "bleed air" for essential aircraft systems operation even though an aircraft electrical system failure may have occurred.